From U.S. Pat. No. 3,989,952 HOHMANN a dental apparatus is known which is provided with a plurality of instruments and electrically or pneumatically driven drive devices. Each drive device may be actuated by means of a foot controlled arrangement or alternatively by a hand controlled means. Furthermore, the dental apparatus has a support arrangement for the drive devices, so that upon withdrawal of a drive device from its support a switch is closed thus permitting actuation of the drive device. Once the drive device is withdrawn from its support it may be erroneously or unintentionally actuated.